Buffer mechanism



Octl13, 1936. e. H. zoucK -BUFFER MECHANI SM "Filed Sept. 29, 1954 3 Sheets-Sheet 1 INVENTOR.

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ATTORNEYJ,

Get. 13, 1936. G. H. zoucK BUFFER MECHANISM Filed Sept. 29, 1934 3 Sheets-Sheet 3 INVENTOR v nwv ATTORNEYS Patented Oct. 13, 1936 were STATES PATENT OFFIE BUFFER MECHANISM Application September 29, 1934, Serial No. 746,027

3 Claims. (Cl. 213%221) This invention relates to buffer mechanism which is particularly adapted for use between an engine and tender which are coupled by a draw bar.

In prior mechanisms of this general type it has been common to employ a chafing plate on the engine which is curved transversely substantially on a radius equal to the distance from the plate to the center of the coupling pin which connects the draw bar to the locomotive frame.

A similar plate is ordinarily employed on the tender and curved about thepin which couples the draw bar with the tender frame. I- Ieretofore, in common constructions of this type, some resilient mechanism has been employed behind one or the other of the chafing plates and a floating block having concave surfaces has been interposed between the two plates, the resilient mechanism serving to maintain contact between the concave and convex surfaces and to urge the engine and tender away from each other and thus place the draw bar under tension. Buffer mechanisms having members with surfaces curved in the manner referred to are usually known as radial buflers.

The present invention has reference to improvements in radial buffers, and in considering one of the most outstanding objects of the invention it is first pointed out that the floating chafing block slides across the surfaces of the chafing plates when the engine and tender become relatively angled, as when rounding curves. In operation, the floating block always occupies a centralized'position with reference to a line joining the draw bar coupling pins.

In an arrangement of this kind, resilient or yielding mechanism mounted behind one of the chafing plates carried on the engine and tender can react between the vehicle frames and also receive bufiing shocks centrally thereof only when the engine and tender are in alignment with each other. The reason for this, of course, is that the floating chafing block moves to one side or the other when the engine and tender frames become relatively angled, and thus moves away from a central position with reference to one or both of the radial chafing plates of the two vehicles. This has heretofore produced uneven and irregular stresses and thrusts on the resilient mechanism, and it is an outstanding object of this invention to overcome this difficulty.

According to the present invention, a resilient mechanism is incorporated within the floating chafing device itself, in view of which all shocks and-forces are centralized in the resilient mechanism under all conditions of angularity of the engine and tender frames.

It should further be noted that the resilient mechanism of a buffer of this type, as disclosed, for example, in my copending application Serial No. 686,203, filed August 22nd, 1933, should have very great resistance tocompression, the resistance to compression preferably being sufiicient to resist all normal compression shocks and thus normally maintain the draw bar under tension. 10 With this in View, multiple resilient or cushion devices are desirably employed, and these are advantageously divided into units or groups positioned in side by side relation transversely of the coupled vehicles. With constructions of this type 15 as heretofore employed (i. e., with the units of the resilient mechanism disposed behind one of the radial chafing plates), when the floating block moves toward one side or the other bufling shocks are irregularly and unevenly distributed 20 between the several units of the resilient mechanism. As contrasted with this prior practice, the arrangement of the present invention always maintains the several units of the resilient mechanism in the same uniform and symmetrical relation with respect to the line on which buffing shocks are'transmitted from one vehicle to the other.

Another important advantage of the present invention resides in the fact that larger and more 30 powerful cushioning and yielding means may be employed within a given overall buffer length, the reasons for this being pointed out more specifically herebelow. It is here noted, however, that this is of importance, especially in the more modern large and heavy locomotives, for the reason that the available space for the buffer mechanism is not increased in proportion to increase in size of the locomotive Other objects and advantages of the invention will be brought out from time to time in the following description which makes reference to the accompanying drawings illustrating two forms of mechanism incorporating features of this invention.

In the drawings- Figure 1 is a plan view of portions of an 'en-. gine and tender frame with a buffer mechanism constructed in accordance with this invention interposed therebetween, a portion of the buffer being illustrated in horizontal section;

Figure 2 is a side view, with parts in section and parts in elevation, of the mechanism appearing in Figure 1;

Figure 3 is a vertical sectional view through a part of the mechanism of Figures 1 and 2, on an enlarged scale, the view being taken as indicated by the section line 33 of Figure 4;

Figure 4 is a partial elevational and partial sectional view taken substantially as indicated by the section line 44 of Figure 1;

Figure 5 is a View similar to Figure 1 but illustrating the engine and tender frames in relatively angled positions;

Figure 6 is a view similar to Figure 1 of a modified form of construction; and

Figure 7 is a side view, partly in section, of the structure of Figure 6.

In the arrangement of Figures 1 to 5 inclusive, the engine frame appears at 8 and the tender frame at 9. These frames are connected by means of a draw bar or draw bars such as shown at I0 and II in Figure 2. The ends of these bars are apertured to receive draw bar coupling pins I2 and I3. As indicated at I4 (left end of Figure 2) at least one of the apertures in the service bar II] has a somewhat loose fit with reference to the associated coupling pin. The safety bar II also has some clearance in at least one of its pin apertures, as is indicated at I5, and the two apertures of the safety bar are preferably spaced a greater distance apart, so that this bar only comes into operation upon failure of the service bar. Because of the draw bar interconnection between the engine and tender, the frames of these vehicles pivot or swing with relation to each other about the draw bar coupling pins I2 and I3 as centers when irregular or curved trackway is encountered. An example of such tilting or swinging of the frames is indicated in Figure 5.

In accordance with the present invention, both the engine and the tender frames are provided with radial chafing plates I6 and H, the plate I6 being transversely curved about the center of draw bar pin I2 and the plate I! being transversely curved about the center of draw bar pin I3. A buffing unit, in the nature of a floating and resilient chafing device, is interposed between the fixed chafing plates I6 and I1, and this device, as herein disclosed, incorporates mechanism for normally keeping the engine and tender frames parted to the limit permitted by the draw bar In. Thus this buffing unit maintains the draw bar under tension under all normal operating conditions. The chafing unit incorporates two relatively movable parts one of which, I8, has a concave surface IBa curved complementarily with respect to the curved surface I'Ia of the chafing plate I'I. At its opposite side, the member I8 has a pair of wedge surfaces I9 joined in an apex which projects away from the curved surface I8a, as clearly seen in Figure 1. From Figures 1 and 3, particularly, it will be seen that the member I8 interfits with the other movable part of the chafing unit, which latter is in the nature of a buffer pocket including a chafing part 20, top and bottom plates 2| and 22 (which embrace member I8), and end walls 2323, all of which parts are formed as a unit, as by being cast integrally. The chafing portion 28 (see Figure 3) has a surface 20a which is transversely curved complementarily to surface I6a of the chafing plate I6, and at its rear face this member also has a pair of wedge surfaces 24 which are similarly formed but oppositely inclined with respect to the wedge surfaces I9.

The chafing unit as a whole may be retained as against dropping down between the chafing plates I6 and I! by means of a depending lip or flange 25 formed on member 20 and engaging behind an upright flange 26 formed on member I6. If desired, an additional depending lip 21 may be formed on member I8 to engage behind the curved flange 28 formed on the chafing plate IT, as is shown in the drawings, and it might be noted that this construction is advantageous in preventing cocking and maintaining alignment between the two relatively movable parts of the chafing unit.

The mechanism for relatively separating members I8 and 20 and thus for maintaining the engine and tender frames 8 and 9 separated from each other and for placing tension on the draw bar, includes a pair of wedges 29-49 which have wedge surfaces complementary to the opposed pairs of surfaces I9-24 which are formed on the members I8 and 28. With the configuration and angling of wedge surfaces illustrated, movement .of the wedges 29 toward each other causes separation of members I8 and 28, and these wedges are urged toward each other by some yielding or resilient means such as springs 30 which are nested within the wedges themselves and. which react against flanged abutment collars 3|. The collars 3|, in turn, bear against displaceable elements 32 which take the form of inverted U-shaped members (see Figures 2 and 4) which are insertable and removable through apertures 33 formed in the top plate or wall 2I of the chafing unit. The lower ends of the displaceable members 32 also preferably project downwardly through apertures 34 (see Figure 1) in the bottom plate 22.

On inspection of the drawings it will also be seen that the end walls 23 are apertured as at 35 for access to certain spring abutment parts just described. Additionally, a normally inoperative bolt 36 may be inserted through the chafing unit transversely thereof, as indicated in Figure 1, and drawn up with the head and nut engaging collars 3I-3I so as to compress the springs 30 and thus remove the pressure thereof from the removable abutments 32. It will be understood that this bolt serves no function in normal operation, but that it is provided for the purpose of facilitating displacement of the abutments 32 when it is desired to take the mechanism apart or assemble it. Upon displacement of the U-shaped abutments 32 the bolt 36 may be loosened sufficiently to release springs 38, in which event the spring pressure is removed from the contacting surfaces of the bufling mechanism and the tension also removed from the draw bar. This operation may be followed when it is desired to remove the draw bar pins I2 and I3. A similar but reverse order of steps would, of course, be followed when inserting the draw bar pins in coupling the engine and tender. Still further, the normally inoperative bolt 36, after compression of the springs and removal of the abutment members 32, may be taken out, and this permits lateral withdrawal of the abutment collars 31 and springs 38 through apertures 35. Inspection, repairs and the like may be conducted in this manner. I

The manipulative steps referred to above are of considerable advantage in order to avoid the necessity of bringing up a second engine behind the tender for the purpose of compressing the springs, as has been necessary with some prior types of construction when coupling or uncoupling the draw bar, or replacing buffer parts.

As best seen in Figure 3, the two relatively movable parts of the chafing unit may be provided with cooperating abutments 31 and 38 to limit their movement toward each other. An assembly'pin 39 passing through a sIEt 'shapeCl apeF ture in jr'nember i8 and "also'through*apertures in the up-per and lower platesil and 22 maybe employed for the purpose of preventing complete separation of various'fbuffer parts when th chafing unit is being' l-ijandle'dby itself. From-theforegoing description it will be seen that in accordance with this invention, a"radia buffer is provided in which 'theyielding r'nechanism or the means for'maintaining the'draw bar under tension is incorporated in a chafing unit which is mounted to move or float transversely between the two curved chafing plates I6 and I1. As hereinbeforeinentioned, an important ad'vantageof this construction-resides in tl ie fact that when the engine'and tender framesfl and'9 -become angled-with' 'respect to'each .other' (see Figure the chafing unit still maintains 'acene tralized position with reference to the draw bar, i. e.-, with reference we line passing through the draw bar pins. This, of course, is the line on which bufiing shocks are transmitted between the vehicles when their frames are relatively angled.

It will also be noted that, as hereinbefore mentioned, the two devices or units of the yielding mechanism incorporated in the buffer (each unit being composed principally of a wedge 29 and associated springs 30) are always maintained in symmetrical relation with respect to the line passing through the draw bar pins. These characteristics ensure much more uniform buffer action than has been possible heretofore.

Another advantage which flows from my improved construction as compared with prior bufi'er mechanisms, resides in the fact that a more truly radial buffing action is maintained under all conditions of use including a badly 'worn condition. For the best possible radial action, the surfaces Ilia and Ha of plates l6 and I! should preferably be maintained fixed with reference to the centers of the draw bar pins l2 and I3. If the resilient mechanism of the buffer is incorporated behind one or the other of the plates l8 and IT, this plate will obviously be advanced to take up whatever wear accumulates on any of the buffer parts. With the arrangement of the present invention, the surfaces Ilia and Ha are always retained fixed with reference to their centers of curvature, and wear of the parts or of the draw bar and its coupling pins is compensated for by an expansion of the floating chafing unit.

Still another advantage of the mechanism described is that, with a given draw bar length,

larger and more powerful buffer wedges, springs and the like may be incorporated within the buffer mechanism considered as a whole, when these wedge and spring devices are built into the floating chafing unit, as compared with the prior practice of disposing the wedges and springs behind one of the radial chafing plates. Conversely, a buffer mechanism of given resistance to compression or strength may have a smaller overall dimension lengthwise of the draw bar when the wedges and springs are incorporated in the floating unit, as compared with prior constructions. One reason for this is that the shape of the wedges and of. the surfaces Ba and Na of the chafing plates are such as to interfit much more compactly in the construction of this application than in arrangements where the wedges are placed behind one of the chafing plates. This will be apparent from inspection of Figures 1 and 5 in which it will be seen that the small ends of the wedges are positioned adjacent each other at the central part of the mechanism, inwvliich regionthe"*surfaces IBa kind" "a have 'their lmi'nlmum'spacing. With regard to 'this'matter, itis notedthat it is preferable to provide yielding mechanisin'in a buffer of this type having suflicient' resistance to'compressi'on, so that the draw bar is maintained under tension underall normal conditions of omration. The reasons for thi'sare more-fully set forth in my copending application Serial Nob-686,203. Normally, therefore, the buffer performs a function beyond a merecushioning device, and in order to provide-this type of operation very powerful and therefore sizable resilient devices are necessary; In: view of' this; it will be seen that it is 'of material importance to permit increasing the size of-theyielding elem'e'n-ts of the buffer without'increasing the overall "dimension rof the buffer lengthwise of' the draw bar." r $311M? At least some of the advantages dis'cussed'above are also secured in the modified construction appearing in Figures 6 and '7. In these views, the

7 engine and tender frames appear again at 8 and 9, and the radial chafing plates at l6 and H. In this arrangement, however, the floating unit takes a somewhat different form. Two interfitting members 40 and 4'! are provided, the member 40 having a surface transversely curved to fit the surface Ilia of chafing plate It, and the member M having a surface curved to fit the surface Ma. The floating unit is illustrated as being supported from the plate l6 by means of lip 42 and flange 43.

The members 40 and M are configured to provide an internal chamber or cavity to receive any suitable mechanism adapted to urge the two parts of the unit away from each other more or less directly, i. e., without the use of transversely movable wedges of the type shown in Figures 1 to 5. Preferably, this yielding mechanism (as in the structure of Figures 1 to 5 inclusive) is divided into two units. In Figures 6 and '7 two sets of springs 44 are shown for this purpose. As in the embodiment first described, the floating unit of the second form also follows the draw bar when curved trackway is encountered. Additionally, the bufling forces are uniformly distributed between the two units of the resilient mechanism, since these units will always bear the same symmetrical relation with respect to a line joining the draw bar pins [2 and I3.

In order to facilitate coupling and uncoupling of the draw bar in this form of mechanism, cooperating pairs of apertured lugs 45 and 46 are provided on members 40 and 4|. Normally inoperative bolts 41 may be employed to draw the member-s40 and ll toward each other and thus compress the springs therebetween and relieve the draw bar tension.

As best seen in Figure 7, an additional feature is here employed (and, if desired, may also be incorporated in the first embodiment). This feature comprises a safety device including. a depending and horizontally projecting shelf or flange 48 carried upon the chafing member l6, and a similar member 49 carried by the member l1. These shelves project respectively below members 4D and 4|, although in the preferable form of construction some clearance is provided so that the shelves would only come into operation to arrest downward movement of the chafing unit in the event of displacement following some abnormal shock or excessive swinging of the engine and tender frames with respect to each other.

-Iclaim:---v a 1. A floating chafing block or device for, use between radial bufiing plates, said device having a concavely curved chafing plate at each of two opposite sides thereof which are relatively movable toward and away from each other, one of said curved chafing plates having oppositely angled wedge surfaces on its reverse side the apex of which lies behind and projects away from the central area of the curved surface, a pair of wedges between said plates with oppositely inclined wedge surfaces complementary to and cooperating with the wedge surfaces first mentioned, and yielding means acting on said wedges to urge them in a direction toward each other, whereby to urge said plates away from each other.

2. A buifer mechanism for use between an engine and tender interconnected by a draw bar, including chafing plates on the engine and tender curved about the draw bar pins as centers, a resiliently expansible floating chafing block between said plates having opposed concavely curved surfaces complementary to the chafing plates, and shelf means carried by one of the vehicles and projecting below the floating block to prevent downward displacement thereof.

3. A buffer mechanism for use between an engine andtender interconnected by a draw bar, including chafing plates on the engine and tender curved about the draw bar pins as centers, a resiliently expansible floating chafing block between said plates having opposed concavely curved surfaces complementary to the chafing plates, means for suspending the block from at least one of the chafing plates, and shelf means carried by one of. the vehicles and projecting below the floating block to prevent downward displacement thereof.

GEORGE H. ZOUCK. 20 

